Dissipation Induced Flat Bands

Abstract

Flat bands are an ideal environment to realize unconventional electronic phases. Here, we show that fermionic systems with dissipation governed by a Bloch Lindbladian can realize dispersionless bands for sufficiently strong coupling to an appropriately engineered bath. These flat bands emerge in a "dark space" of the system-environment coupling and are long-lived by virtue of symmetry protection from dissipation. We exhibit the robustness of this mechanism for general one and two band models with and without spin, and discuss conditions for their experimental realization such as in a 2D material on a superconducting substrate.